This Machine Comes in 2 Different Drive Options from HP and Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive) or (One M.2 NGFF (2280) Solid State Drive using a M.2 Drive Bracket) Note: When the M.2 (2280) Drive is installed, the M.2 Drive occupies the 2.5" Drive bay using a M.2 Drive bracket. If replacing the M.2 Drive for a 2.5" Drive, you will need the 2.5" Drive hardware kit p/n 755740-001 (Includes: 2.5" Drive bracket, connector cable and screws) for installation. If replacing the 2.5" Drive for a M.2 Drive, you will need the M.2 Drive hardware kit p/n 783845-001 (Includes: M.2 Drive top and bottom bracket, PCBA Drive board, connector cable and screws) for installation. (The M.2 Drive board supports SATA only Solid State Drives)